A known approach, to cleanspace-assisted fabrication, is to assemble the manufacturing facility as a “cleanroom.” In such cleanrooms, processing tools are arranged to provide aisle space for human operators or automation equipment. An example text on cleanroom design (referred to herein as “the Whyte text”) is as follows: “Cleanroom Design, Second Edition,” edited by W. Whyte, published by John Wiley & Sons, 1999, ISBN 0-471-94204-9. The Whyte text is incorporated herein by reference in its entirety.
Cleanroom design has evolved over time to include the following techniques. Having processing stations located inside clean hoods. Having vertical unidirectional air flow through a raised floor, with separate cores for the tools and aisles. Having specialized mini-environments that surround only the processing tool for added space cleanliness. The “ballroom” approach, where tools, operators and automation all reside in the same cleanroom.
Evolutionary improvements have enabled higher yields and the production of devices with smaller geometries. However, known cleanroom design has disadvantages and limitations.
For example, as the size of tools has increased and the dimensions of cleanrooms have increased, the volume of cleanspace that is controlled has concomitantly increased. As a result, the cost of building the cleanspace, and the cost of maintaining the cleanliness of such cleanspace, has increased.
Tool installation in a cleanroom can be difficult. The initial “fit up” of a “fab” with tools, when the floor space is relatively empty, can be straight forward. However, as tools are put in place, and a fab begins to process substrates, it can become increasingly difficult, and disruptive of job flow, to either place new tools or remove old ones. It would be desirable to reduce the installation difficulties, attendant to dense tool placement, since denser tool placement otherwise affords substantial economic advantages for cleanroom construction and maintenance.
Another area of evolutionary improvement has come with improvements in robotics. Substrate processing has changed from a manually intensive process where human operators handle substrates or batches of substrates. In current cleanroom designs, the tools can include robotics for substrate handling, with human operators only needing to perform the following functions: loading collections of substrates onto tools, unloading collections of substrates from tools and moving collections of substrates from one tool to another. In some cases, automation performs all handling and logistics operations. Despite the evolutionary advances, cleanroom robotics remain extremely complex. The robotics can therefore be error prone and costly.
It would be desirable to have manufacturing facilities, for cleanspace-assisted fabrication, that use less cleanspace, permit dense tool placement while maintaining ease of installation and permit the use of simpler robotics.